Multimodality is concerned with allowing customers to use communications devices, such as wireless telephones, to interact with applications in an integrated fashion using both voice and visual means. A significant technical impediment in the development of multimodality is that many current wireless devices, such as 2G and 2.5G cell phones are capable of supporting only one mode or channel at a time. For instance, if the customer is interacting through the voice channel (typically, by placing a phone call, either to a human or a computationally-enabled agent), he is typically unable to interact through a visual channel (e.g., he is typically unable to click on the visual display and receive a new browser page, interact with it, send new requests into the network, etc).
One idea used to circumvent this problem is swapping multimodality. Swapping multi-modality refers to the sequential (rather than concurrent) use of voice and visual modes—i.e., the communication can change back and forth between visual and voice modes, but cannot use both at the same time. Implementations of swapping multimodality, however, must solve a fundamental problem: when the user is interacting in the voice mode, and wishes to transfer to visual mode, a means must be found by which the visual mode automatically and transparently displays the current “state” of the user's interaction with the application. For example, suppose that equivalent content is available in both Voice eXtensible Markup Language (VoiceXML) and Wireless Markup Language (WML). If the user is browsing VoiceXML pages on a voice browser and then switches to visual mode, in order to make the swap appear “seamless” to the user it should be possible to point the visual browser to a card in the WML deck that is equivalent to the VoiceXML page that the user last saw when the swap to visual mode occurred. In order to accomplish this results, however, it must be possible to tell the visual browser which card to point to at the time the mode swap occurs.
The present invention provides a technique for furnishing this state information to a browser, and overcomes drawbacks present in the prior art.